Inbred corn line PHR62

ABSTRACT

According to the invention, there is provided an inbred corn line, designated PHR62. This invention thus relates to the plants and seeds of inbred corn line PHR62 and to methods for producing a corn plant produced by crossing the inbred line PHR62 with itself or with another corn plant. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line PHR62 with another corn line or plant and to crosses with related species.

FIELD OF THE INVENTION

This invention i in the field of corn breeding, specifically relating toan inbred corn line designated PHR62.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety/hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and fruit size, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant.

Plants that have been self-pollinated and selected for type for manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twohomozygous lines produce a uniform population of hybrid plants that maybe heterozygous for many gene loci. A cross of two plants eachheterozygous at a number of gene loci will produce a population ofhybrid plants that differ genetically and will not be uniform.

Corn plants (Zea mays L.) can be bred by both self pollination andcross-pollination techniques. Corn has separate male and female flowerson the same plant, located on the tassel and the ear, respectively.Natural pollination occurs in corn when wind blows pollen from thetassels to the silks that protrude from the tops of the incipient ears.

The development of corn hybrids requires the development of homozygousinbred lines, the crossing of these lines, and the evaluation of thecrosses. Pedigree breeding and recurrent selection breeding methods areused to develop inbred lines from breeding populations. Breedingprograms combine the genetic backgrounds from two or more inbred linesor various other broad-based sources into breeding pools from which newinbred lines are developed by selfing and selection of desiredphenotypes. The new inbreds are crossed with other inbred lines and thehybrids from these crosses are evaluated to determine which of thosehave commercial potential.

Pedigree breeding for single-gene traits starts with the crossing of twogenotypes, each of which may have one or more desirable characteristicsthat is lacking in the other or which complement the other. If the twooriginal parents do not provide all of the desired characteristics,other sources can be included in the breeding population. In thepedigree method, superior plants are selfed and selected in successivegenerations. In the succeeding generations the heterozygous condition9ives way to homo9eneous lines as a result of self-pollination andselection. Typically in the pedigree method of breeding five or moregenerations of selfing and selection is practiced: F₁ →F₂ ; F₂ →F₃ ; F₃→F₄ ; F₄ →F₅, etc.

Backcrossing can be used to improve an inbred line. Backcrossingtransfers a specific desirable trait from one inbred or source to aninbred that lacks that trait. This can be accomplished for example byfirst crossing a superior inbred (A) (recurrent parent) to a donorinbred (non-recurrent parent), which carries the appropriate gene(s) forthe trait in question. The progeny of this cross is then mated back tothe superior recurrent parent (A) followed by selection in the resultantprogeny for the desired trait to be transferred from the non-recurrentparent. After five or more backcross generations with selection for thedesired trait, the progeny will be heterozygous for loci controlling thecharacteristic being transferred, but will be like the superior parentfor most or almost all other genes. The last backcross generation wouldbe selfed to give pure breeding progeny for the gene(s) beingtransferred.

A single cross hybrid corn variety is the cross of two inbred lines,each of which has a genotype which complements the genotype of theother. The hybrid progeny of the first generation is designated F₁. Inthe development of hybrids only the F₁ hybrid plants are sought.Preferred F₁ hybrids are more vigorous than their inbred parents. Thishybrid vigor, or heterosis, can be manifested in many polygenic traits,including increased vegetative growth and increased yield.

The development of a hybrid corn variety involves three steps: (1) theselection of plants from various germplasm pools; (2) the selfing of theselected plants for several generations to produce a series of inbredlines, which, although different from each other, each breed true andare highly uniform; and (3) crossing the selected inbred lines withunrelated inbred lines to produce the hybrid progeny (F₁). During theinbreeding process in corn, the vigor of the lines decreases. Vigor isrestored when two unrelated inbred lines are crossed to produce thehybrid progeny (F₁). An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between any twoinbreds will always be the same. Once the inbreds that give a superiorhybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F₁ progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁hybrids is lost in the next generation (F₂). Consequently, seed fromhybrid varieties is not used for planting stock.

Corn is an important and valuable field crop. Thus, a continuing goal ofplant breeders is to develop high yielding corn hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility to environmental stresses. Toaccomplish this goal, the corn breeder must select and develop superiorinbred parental lines for producing hybrids. This requiresidentification and selection of genetically unique individuals which ina segregating population occur as the result of a combination ofcrossover events plus the independent assortment of specificcombinations of alleles at many gene loci which results in specificgenotypes. Based on the number of segregating genes, the frequency ofoccurrence of an individual with a specific genotype is less than 1 in10,000. Thus, even if the entire genotype of the parents has beencharacterized and the desired genotype is known, only a few if anyindividuals having the desired genotype may be found in a large F₂ or S₀population. Typically, however, the genotype of neither the parents northe desired genotype is known in any detail.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred corn line,designated PHR62. This invention thus relates to the seeds of inbredcorn line PHR62, to the plants of inbred corn line PHR62, and to methodsfor producing a corn plant produced by crossing the inbred line PHR62with itself or another corn line. This invention further relates tohybrid corn seeds and plants produced by crossing the inbred line PHR62with another corn line or a related species.

DEFINITIONS

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

BAR PLT=BARREN PLANTS. This is the number of plants per plot that werenot barren (lack ears).

BRT STK =BRITTLE STALKS. This is a measure of the stalk breakage nearthe time of pollination, and is an indication of whether a hybrid orinbred would snap or break near the time of flowering under severewinds. Data are presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Actual yield of the grain at harvestadjusted to 15.5% moisture. ABS is in absolute terms and % MN is percentof the mean for the experiments in which the inbred or hybrid was grown.

CLD TST=COLD TEST. This is the percentage of kernels that germinateunder cold soil conditions. ABS=absolute measurement and % MN ispercentage of mean of the experiments in which inbred or hybrid wasgrown.

COB SC=COB SCORE. The cob score is a rating of how well the grain isshelled off the cob and how badly the cob is broken up going through thecombine. This is given as a 1 to 9 score with 9 being very good. A highscore indicates that the grain shells off of the cob well, and the cobdoes not break.

DRP EAR=DROPPED EARS. This is a measure of the number of dropped earsper plot and represents the percentage of plants that did not drop earsprior to harvest.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to thetop developed ear node attachment and is measured in inches.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on a perplot basis for the inbred or hybrid.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GRN QUL=GRAIN QUALITY. This is a 1 to 9 rating for the general qualityof the shelled grain as it is harvested based on such factors as thecolor of the harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

KER LB=KERNELS PER POUND. This is the number of kernels per 0.1 pound.

KSZ L=KERNEL SIZE LARGE. Percentage by weight of shelled corn thatpasses through a screen with 25/64 inch diameter openings but does notpass through a screen with 22/64 inch diameter openings.

KSZ MF=KERNEL SIZE MEDIUM FLAT. Percentage by weight of shelled cornthat passes through a screen with 22/64 inch diameter openings and ascreen with 13/64 inch wide slot screen but does not pass through ascreen with 18.5/64 inch diameter openings.

KSZ MR=KERNEL SIZE MEDIUM ROUND. Percentage by weight of shelled cornthat passes through a screen with 22/64 inch diameter openings but doesnot pass through a 13/64 inch wide slot screen or a screen with 18.5/64inch diameter openings.

KSZ S=KERNEL SIZE SMALL. Percentage by weight of shelled corn thatpasses through a screen with 18.5/64 inch diameter openings but does notpass through a screen with 16/64 inch diameter openings.

KSZ TIP=KERNEL SIZE TIPS. Percentage by weight of shelled corn thatpasses through a screen with 16/64 inch diameter openings.

KSZ XL=KERNEL SIZE EXTRA LARGE. Percentage by weight of shelled cornthat does not pass through a screen with 25/64 inch diameter openings.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in inches.

POL WT=POLLEN WEIGHT. This is the weight of pollen per 100 plants takenon a plot basis. ABS refers to data in absolute, and % MN refers to datapresented as percentage of experimental mean.

PRM=PREDICTED RM. This trait, predicted relative maturity (RM), is basedon the harvest moisture of the grain. The relative maturity rating isbased on a known set of checks and utilizes standard linear regressionanalyses and is referred to as the Minnesota Relative Maturity RatingSystem.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that donot root lodge; plants that lean from the vertical axis at anapproximately 30° angle or greater would be counted as root lodged.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A cornbreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

STA GRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STK CNT - NUMBER OF PLANTS. This is the final stand or number of plantsper plot.

STK LDG=STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at timeof flowering. A 1 would indicate a very high level of blasting at timeof flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data is given as percentage of tillers:number of tillers per plot divided by number of plants per plot.

TST WT=TEST WEIGHT UNADJUSTED. The measure of the weight of the grain inpounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain inpounds for a given volume (bushel) adjusted for percent moisture.

YLD=YIELD. It is the same as BU ACR ABS.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

CLN=Corn Lethal Necrosis (MCMV=Maize Chlorotic Mottle Virus andMDMV=Maize Dwarf Mosaic Virus): Visual rating (1-9 score) where a "1" isvery susceptible and a "9" is very resistant.

MDM CPX=Maize Dwarf Mosaic Complex (MDMV=Maize Dwarf Mosaic Virus &MCDV=Maize Chlorotic Dwarf Virus): Visual rating (1-9 score) where a "1"is very susceptible and a "9" is very resistant.

COM SMT=Common Smut (Ustilago maydis): Percentage of plants that did nothave infection.

ANT ROT Anthracnose Stalk Rot (Colletotrichum graminicola): Visualrating (1-9 score) where a "1" is very susceptible and a "9" is veryresistant.

SLF BLT=Southern Leaf Blight (Bipolaris maydis, Helminthosporiummaydis): Visual rating (1-9 score) where a "1" is very susceptible and a"9" is very resistant.

NLF BLT=Northern Leaf Blight (Exserohilum turcicum, H. turcicum): Visualrating (1-9 score) where a "1" is very susceptible and a "9" is veryresistant.

HC BLT=Helminthosporium Carbonum Leaf Blight (Bipolariszeicola, H.carbonum): Visual rating (1-9 score) where a "1" is very susceptible anda "9" is very resistant.

COM RST=Common Rust (Puccinia sorghi): Visual rating (1-9 score) where a"1" is very susceptible and a "9" is very resistant.

SO RST=Southern Rust (Puccinia polysora): Visual rating (1-9 score)where a "1" is very susceptible and a "9" is very resistant.

EYE SPT=Eyespot (Kabatiella zeae): Visual rating (1-9 score) where a "1"is very susceptible and a "9" is very resistant.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis): Visual rating (1-9score) where a "1" is very susceptible and a "9" is very resistant.

STW WLT=Stewart's Wilt (Erwinia stewartii): Visual rating (1-9 score)where a "1" is very susceptible and a "9" is very resistant.

GOS WLT=Goss's Wilt (Corynebacterium nebraskense): Visual rating (1-9score) where a "1" is very susceptible and a "9" is very resistant.

HD SMT=Head Smut (Spacelotheca reiliana): Percentage of plants that didnot have infection.

DNY MIL=Downy Mildew (Peronosclerospora sorghi): Percentage of plantsthat did not have infection.

FUS EAR=Fusarium Ear Mold (Fusarium moniliforme): Percentage of plantsthat did not have infection.

EAR MLD=General Ear Mold: Visual rating (1-9 score) where a "1" is verysusceptible and a "9" is very resistant. This is based on overall ratingfor ear mold of mature ears without determining specific mold organism,and may not be predictive for a specific ear mold.

ECB DPE=Dropped ears due to European Corn Borer (Ostrinia nubilalis):Percentage of plants that did not drop ears under second brood cornborer infestation.

ECB 2SC=European Corn Borer Second Brood (Ostrinia nubilalis): Visualrating (1-9 score) of post flowering damage due to infestation byEuropean Corn Borer. A "1" is very susceptible and a "9" is veryresistant.

ECB lLF=European Corn Borer First Brood (Ostrinia nubilalis): Visualrating (1-9 score) of pre-flowering leaf feeding by European Corn Borer.A "1" is very susceptible and a "9" is very resistant.

ECB 2IT=European Corn Borer Second Brood Tunneling (Ostrinia nubilalis):The average inches of tunneling in the stalk due to second brood(post-flowering) European Corn Borer infestation. Determined bysplitting stalks with a knife, from four internodes above the ear to theground.

DETAILED DESCRIPTION OF THE INVENTION

Inbred Corn Line PHR62 is a yellow, dent corn inbred with superiorcharacteristics and provides an acceptable male or female parental linein crosses for producing first generation F₁ corn hybrids. PHR62 isadapted over most regions of the United States. The inbred can be usedto produce hybrids from approximately 105-118 relative maturity based onthe Minnesota Relative Maturity Rating System for harvest moisture ofgrain. PHR62 should make an excellent female parent because of itsabove-average yield and excellent seedling vigor. PHR62 is also veryacceptable as a male parent because of its heavy pollen yield. Theinbred was 132% of the experiment mean for amount of pollen averagedover 12 locations in the pollen yield test.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows. Most of the data in theVariety Description Information was collected at Johnston, Iowa. Theinbred has been self-pollinated and ear-rowed a sufficient number ofgenerations with careful attention paid to uniformity of plant type toensure homozygosity and phenotypic stability. The line has beenincreased both by hand and in isolated fields with continued observationfor uniformity. No variant traits have been observed or are expected inPHR62.

Inbred corn line PHR62, being substantially homozygous, can bereproduced by planting seeds of the line, growing the resulting cornplants under self-pollinating or sibpollinating conditions with adequateisolation, and harvesting the resulting seed, using techniques familiarto the agricultural arts.

                  TABLE 1                                                         ______________________________________                                        PHR62                                                                         VARIETY DESCRIPTION INFORMATION                                               ______________________________________                                        Type: Dent    Region Best Adapted: Most Regions                               A.     Maturity: Average across maturity zones. Zone: 0                                 INBRED = PHR62                                                             Heat Unit Shed: 1490                                                          Heat Unit Silk: 1540                                                             No. Reps: 66                                                        HEAT UNITS =                                                                   ##STR1##                                                                     ______________________________________                                         *If maximum is greater than 86 degrees fahrenheit, then 86 is used and if     minimum is less than 50, then 50 is used. Heat units accumulated daily an     can not be less than 0.                                                  

B. Plant Characteristics:

Plant height (to tassel tip): 245 cm

Length of top ear internode: 13 cm

Number of ears per stalk: Single with slight two eared

tendency Ear height (to base of top ear): 101 cm

Number of tillers: None

Cytoplasm type: Normal

C. Leaf:

Color: (WF9) Medium green

Angle from Stalk: 30-60 degrees

Marginal Waves: (OH7L) Many

Number of Leaves (mature plants): 19

Sheath Pubescence: (W22) Light

Longitudinal Creases: (PAll) Many

Length (Ear node leaf): 76 cm

Width (widest point, ear node leaf): 8 cm

D. Tassel:

Number lateral branches: 9

Branch Angle from central spike: 30-40 degrees

Pollen Shed: Heavy base on pollen Yield Test (132% of experiment mean)

Peduncle Length (top leaf to basal branches): 21 cm

Anther Color: Reddish Pink

Glume Color: Green

E. Ear (Husked Ear Data Except When Stated Otherwise):

Length: 17 cm

Weight: 133 gm

Mid-point Diameter: 46 mm

Silk Color: Yellow

Husk Extension (Harvest stage): Long (8-10 cm beyond ear tip)

Husk Leaf: Long (>15cm)

Taper of Ear: Slight taper

Position of Shank (dry husks): Upright

Kernel Rows: Straight, Distinct, Number=16

Husk Color (fresh): Light green

Husk Color (dry): Buff

Shank Length: 21 cm

Shank (No. of internodes): 7

F. Kernel (Dried):

Size (from ear mid-point)

Length: 11 mm

Width: 8 mm

Thick: 5 mm

Shape Grade (% rounds): 40-60 % medium rounds based on

Parent Test Data

Pericarp Color: Colorless

Aleurone Color: Homozygous yellow

Endosperm Color: Yellow

Endosperm Type: Normal

Gm Wt/100 Seeds (unsized): 25 gm

G. Cob:

Diameter at mid-point: 29 mm

Strength: Strong

Color: Red

H. Diseases:

Corn Lethal Necrosis (MCMV=Maize Chlorotic Mottle Virus and MDMV=MaizeDwarf Mosaic Virus): Susceptible

Maize Dwarf Mosaic Complex (MDMV & MCDV=Maize Chlorotic

Dwarf Virus): Susceptible

Anthracnose Stalk Rot (C. Graminicola): Intermediate

S. Leaf Blight (H. Maydis): Intermediate

N. Leaf Blight (H. Turcicum): Intermediate

Carbonum Leaf Blight (H. Carbonum): Intermediate

Common Rust (P. Sorghi): Intermediate

Eye Spot (K. Zeae): Intermediate

Gray Leaf Spot (C. Zeae): Susceptible

Stewarts Wilt (E. Stewartii): Intermediate

Goss's Wilt (C. Nebraskense): Intermediate

Common Smut (U. Maydis): Resistant

Head Smut (S. Reiliana): Intermediate

Downy Mildew (S. Sorghi): Intermediate

Fusarium Ear Mold (F. Moniliforme): Intermediate

I. Insects:

European Corn Borer-1 Leaf Damage (Pre-flowering):

Intermediate

European Corn Borer-2 (Post-flowering): Intermediate

    ______________________________________                                        J. Variety Most Closely Resembling:                                                  Character                                                                             Inbred                                                         ______________________________________                                               Maturity                                                                              PHZ51                                                                 Usage   PHV78                                                          ______________________________________                                    

PHV78 (PVP Certificate No.8800003 and Patent No. 4,812,599) is a PioneerHi-Bred International, Inc. proprietary inbred. PHZ51 (PVP Certificate8600132) is a Pioneer Hi-Bred proprietary inbred with less usage thanPHV78 but is closer to PHR62 for maturity.

Items B, C, D, E, F, and G are based primarily on a maximum of threereps of data from Johnston, Iowa from 1987 and 1988, plus descriptioninformation from the maintaining station.

TABLE 2 ELECTROPHORESIS RESULTS Isozyme Genotypes for PHR62

Isozyme data was generated for inbred corn line PHR62 according to theprocedure described in Goodman, M.M. and Stuber, C.M., "Geneticidentification of lines and crosses using isoenzyme electrophoresis,"Proceedings of the Thirty Fifth Annual Corn and Sorghum IndustryResearch Conference, Chicago, Illinois (1980).

    ______________________________________                                        Alleles Present                                                                       Loci  PHR62                                                           ______________________________________                                                ACP1  4                                                                       ADH1  4                                                                       CAT3  9                                                                       DIA18 8                                                                       GOT1  4                                                                       GOT2  4                                                                       GOT3  4                                                                       IDH1  4                                                                       IDH2  6                                                                       MDH1  6                                                                       MDH2  3.5                                                                     MDH3  16                                                                      MDH4  12                                                                      MDH5  12                                                                      MMM   4                                                                       PGM1  9                                                                       PGM2  3                                                                       PGD1  3.8                                                                     PGD2  5                                                                       PHI1  4                                                               ______________________________________                                    

INDUSTRIAL APPLICABILITY

This invention also is directed to methods for producing a corn plant bycrossing a first parent corn plant with a second parent corn plantwherein the first or second parent corn plant is an inbred corn plantfrom the line PHR62. Further, both first and second parent corn plantscan come from the inbred corn line PHR62. Thus, any such methods usingthe inbred corn line PHR62 are part of this invention: selfing,backcrosses, hybrid production, crosses to populations, and the like.All plants produced using inbred corn line PHR62 as a parent are withinthe scope of this invention. Advantageously, the inbred corn line isused in crosses with other, different, corn inbreds to produce firstgeneration (F₁) corn hybrid seeds and plants with superiorcharacteristics.

As used herein, the terms "plant and plant parts" include plant cells,plant protoplasts, plant cell tissue culture from which corn plants canbe regenerated, plant calli, plant clumps, and plant cells that areintact in plants or parts of plants, such as embryos, pollen, flowers,kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers,silk and the like.

Tissue culture of corn is described in European Patent Application,publication 160,390, incorporated herein by reference. Corn tissueculture procedures are also described in Green and Rhodes, "PlantRegeneration in Tissue Culture of Maize," Maize for Biological Research(Plant Molecular Biology Association, Charlottsville, Virginia

1982, at 367-372. Thus, another aspect of this invention is to providecells which upon growth and differentiation produce the inbred linePHR62.

The utility of inbred line PHR62 also extends to crosses with otherspecies. Commonly, suitable species will be of the family Graminaceae,and especially of the genera Zea, Tripsacum, Coix, Schlerachne,Polytoca, Chionachne, and Trilobachne, of the tribe Maydeae. Of these,Zea and Tripsacum, are most preferred. Potentially suitable for crosseswith PHR62 may be the various varieties of grain sorghum, Sorghumbicolor (L.) Moench.

Corn is used as human food, livestock feed, and as raw material inindustry. The food uses of corn, in addition to human consumption ofcorn kernels, include both products of dry- and wet-milling industries.The principal products of corn dry milling are grits, meal and flour.The corn wet milling industry can provide corn starch, corn syrups, anddextrose for food use. Corn oil is recovered from corn germ, which is aby-product of both dry- and wet-milling industries.

Corn, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of corn are mainly from corn starch from the wet-millingindustry and corn flour from the dry-milling industry. The industrialapplications of corn starch and flour are based on functionalproperties, such as viscosity, film formation, adhesive properties, andability to suspend particles. The corn starch and flour have applicationin the paper and textile industries. Other industrial uses includeapplications in adhesives, building materials, foundry binders, laundrystarches, explosives, oil-well muds, and other mining applications.

Plant parts other than the grain of corn are also used in industry.Stalks and husks are made into paper and wallboard and cobs are used forfuel and to make charcoal.

The seed of inbred corn line PHR62, the plant produced from the inbredseed, the hybrid corn plant produced from the crossing of the inbred,hybrid seed, and various parts of the hybrid corn plant can be utilizedfor human food, livestock feed, and as a raw material in industry.

EXAMPLE INBRED AND HYBRID PERFORMANCE OF PHR62

In the examples that follow the traits and characteristics of inbredcorn line PHR62 are given as a line and in hybrid combination. The datacollected on inbred corn line PHR62 is presented for the keycharacteristics and traits.

The results in Table 3 compare PHR62 to PHV78. PHV78 (PVP Certificate#8800003, Patent No. 4,812,599) is an important inbred that would beused in some of the area that PHR62 would be used and would cross wellwith some of the same inbred lines. This research data has beencollected over three years of testing. The results show that the twolines differ for a number of traits. PHR62 is an earlier maturing inbredfor flowering and harvest moisture of the grain and is somewhat shorterbut has higher ear placement than PHV78. PHR62 has much better grainquality, with harder textured and higher test weight grain than PHV78.Both lines are good males but PHR62 is acceptable as a female whilePHV78 is not acceptable as a female for hybrid production. In the areasof disease and insect resistance, PHR62 shows greater resistance to earmold.

The results in Table 4 compare PHR62 to PHV78 crossed to the same inbredtesters. These results show that the two lines also differ for a numberof traits in hybrid combination. The PHR62 hybrids mature earlier forharvest grain moisture and pollen shed than the PHV78 hybrids. They alsoshow more resistance to root lodging, have a higher grain test weightand higher grain quality than the PHV78 hybrids. The earlier maturityand improved grain quality and test weight allow PHR62 hybrids to beutilized farther north and complement PHV78 hybrids with improved testweight and grain quality. PHR62 has given good performance in specifichybrid combinations.

                                      TABLE 3                                     __________________________________________________________________________    PAIRED INBRED COMPARISON DATA                                                 INBRED #1 - PHR62                                                             INBRED #2 - PHV78                                                                          BU  BU   BAR BRT EAR EAR  EST CLD CLD  DRP                               VAR  ACR ACR  PLT STK HT  SZ   CNT TST TST  EAR                       YEAR    #    ABS % MN ABS ABS ABS ABS  ABS ABS % MN ABS                       __________________________________________________________________________    TOTAL SUM                                                                             1    66.8                                                                              93   88.2                                                                              99.1                                                                              34.0                                                                              5.8  24.1                                                                              79.0                                                                              95   99.7                              2    80.6                                                                              117  87.7                                                                              96.4                                                                              32.4                                                                              7.3  23.8                                                                              71.0                                                                              85   100.0                             LOCS 6   6    11  5   27  16   69  1   1    5                                 DIFF 13.9                                                                              24   0.5 2.7 1.6 1.4  0.2 8.0 10   0.3                               PROB .095*                                                                             .064*                                                                              .759                                                                              .409                                                                              .133                                                                              .000#                                                                              .706         .374                      __________________________________________________________________________                 TIL GDU  GDU  GRN       PLT  POL  RT   TAS                               VAR  LER SHD  SLK  QUL  MST  HT   SC   LDG  BLS                       YEAR    #    ABS ABS  ABS  ABS  ABS  ABS  ABS  ABS  ABS                       __________________________________________________________________________    TOTAL SUM                                                                             1    2.1 149.3                                                                              156.2                                                                              6.4  20.0 81.4 5.6  32.0 9.0                               2    2.5 158.4                                                                              165.0                                                                              4.4  24.9 84.8 6.5  91.3 9.0                               LOCS 18  69   64   7    6    28   31   1    1                                 DIFF 0.4 9.1  8.8  2.0  5.0  3.3  0.9  59.3 0.0                               PROB .752                                                                              .000#                                                                              .000#                                                                              .019+                                                                              .000#                                                                              .015+                                                                              .011+                               __________________________________________________________________________                 TAS  TEX  TST  SCT  SDG  STA  STK STK  YLD                               VAR  SZ   EAR  WT   GRN  VGR  GRN  CNT LDG  SC                        YEAR    #    ABS  ABS  ABS  ABS  ABS  ABS  ABS ABS  ABS                       __________________________________________________________________________    TOTAL SUM                                                                             1    6.1  7.3  55.2 6.0  5.2  5.1  22.9                                                                              93.6 5.9                               2    7.4  4.3  53.0 5.3  4.9  6.7  23.1                                                                              93.6 6.1                               LOCS 29   12   6    26   37   17   49  6    27                                DIFF 1.3  3.0  2.2  0.7  0.3  1.6  0.3 0.1  0.2                               PROB .000#                                                                              .000#                                                                              .001#                                                                              .128 .270 .000#                                                                              .633                                                                              .984 .465                      __________________________________________________________________________                COM COM EAR ECB                                                                              ECB                                                                              ECB                                                                              EYE                                                                              GLF HC NLF                                                                              SLF                                                                              SO STW                               VAR RST SMT MLD DPE                                                                              1LF                                                                              2SC                                                                              SPT                                                                              SPT BLT                                                                              BLT                                                                              BLT                                                                              RST                                                                              WLT                       YEAR    #   ABS ABS ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                       __________________________________________________________________________    TOTAL SUM                                                                             1   5.5 0.0 7.4 43.3                                                                             6.5                                                                              5.7                                                                              4.0                                                                              2.8 7.0                                                                              4.7                                                                              4.5                                                                              4.5                                                                              7.0                               2   5.3 1.0 5.2 73.3                                                                             5.8                                                                              4.6                                                                              3.0                                                                              3.2 6.0                                                                              6.0                                                                              4.5                                                                              6.0                                                                              7.5                               LOCS                                                                              3   1   23  1  19 6  1  3   1  3  2  1  2                                 DIFF                                                                              0.2 1.0 2.2 30.0                                                                             0.7                                                                              1.1                                                                              1.0                                                                              0.3 1.0                                                                              1.3                                                                              0.0                                                                              1.5                                                                              0.5                               PROB                                                                              .932    .000#  .102                                                                             .193  .667   .423                                                                             1.00  .500                      __________________________________________________________________________     * = 10% SIG                                                                   + = 5% SIG                                                                    # = 1% SIG                                                               

                                      TABLE 4                                     __________________________________________________________________________    Average Inbred by Tester Performance Comparing PHR62 to PHV78 crossed         to the same Inbred Testers and Grown in the Same Experiments. All             Values are Expressed as percent of the experiment mean except Predicted       RM, Selection Index, and Yield (Bu./Ac.).                                                      SEL                                                                              BU        GDU STK RT  BAR                                                                              STA TST COB                             Inbred                                                                              PRM IND                                                                              ACR                                                                              YLD                                                                              MST SHD LDG LDG PLT                                                                              GRN WTA SC                       __________________________________________________________________________    TOTAL  REPLIC.                                                                             73  73 73 73 73  17  72  7   20 59  73                           MEAN WTS                                                                             PHR62 115 95 120                                                                              92 91  100 101 112 101                                                                              81  101                          MEAN WTS                                                                             PHV78 123 104                                                                              136                                                                              106                                                                              108 103 102 87  100                                                                              119 99                                  DIFF. 7   8  16 13 17  2   1   24  0  39  1                            __________________________________________________________________________                                    GRN SDG EST                                                                              PLT                                                                              EAR                                                                              DRP BRT                                                Inbred                                                                              QUL VGR CNT                                                                              HT HT EAR STK                      __________________________________________________________________________                       TOTAL  REPLIC.                                                                             49  30  64 30 30 66                                              MEAN WTS                                                                             PHR62 106 91  91 100                                                                              102                                                                              100                                             MEAN WTS                                                                             PHV78 100 106 102                                                                              102                                                                              101                                                                              100                                                    DIFF. 6   15  11 1  0  0                            __________________________________________________________________________

Applicant has made available to the public without restriction a depositof at least 2500 seeds of inbred PHR62 with the American Type CultureCollection (ATCC), Rockville, MD 20852 USA, ATCC Deposit No. 75079. Theseeds deposited with the ATCC are taken from the same deposit maintainedby Pioneer HI-Bred International Inc., 700 Capital Square, 400 LocustStreet, Des Moines, Iowa 50309 since prior to the filing date of thisapplication. The deposit will be maintained in the ATCC depository,which is a public depository, for a period of 30 years, or 5 years afterthe most recent request, or for the effective life of the patent,whichever is longer, and will be replaced if it becomes nonviable duringthat period.

What is claimed is:
 1. Inbred corn seed designated PHR62 having ATCCoccursion No.
 2. A corn plant produced by the seed of claim
 1. 3. Tissueclulture of the plant of claim
 2. 4. Tissue culture according to claim 3comprising regenerable cells of a plant part selected from meristematictissue, anthers, leaves, embryos, protoplasts, and pollen.
 5. A cornplant regenerated from the regenerable cells of a tissue cultureaccording to claim
 4. 6. An inbred corn plant having all thephysiological and morphological characteristics of the seed of claim 1.